Rear end

Does anybody know what the problem is

Hello, I'm Danny
To be honest the howling sound in a rear differential with 200K miles is usually the gearset just being worn out.The clunking is also related to just being high mileage or possible worn u-joints in the driveshaft.These are both easily repairable.You should go to a repair shop the specializes in drivelines and have them take a listen to the sound and inspect the u-joints.Here is a tutorial showing how a differential works.

https://www.2carpros.com/articles/how-a-differential-works

Hope this helps and thanks for using 2CarPros.
Danny-

One more thing I drove my truck today put it in 4wd sound was louder the howling then put it in 2wd and drove it didn’t make the sound and I drove it for a few hours do you know anything about that

Hello again
The 4x4 transfer case requires oil changes as well.That is what couples the front and rear differentials together when the 4 wheel drive is engaged.Have you performed routine service on the differentials as well as the transfer case? Your cars specifications are below.Hope this helps and thanks again for using 2CarPros.
Danny-

Can you please shoot a quick video with your phone so we can hear the noise, that would be great. You can upload it here with your response?